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Health Professionals

In this Section:


Index of Orthodontic Treatment Need (IOTN) was introduced on 1 October 2011, in PCA(D)(2011)6, as a means of assessing the requirement of orthodontic treatment under general dental services arrangements.

Orthodontists will assess the requirement for orthodontic treatment using the dental health component (DHC) and the aesthetic component (AC).

Study Models

Orthodontic cases graded at 3.6 to 3.10 and 4 require study models to be provided at the time of request for approval. A payment for duplicate study models will be made for these.

Cases assessed as IOTN Grade 5 do not require duplicate study models, therefore, no duplicates are to be claimed unless they are requested by the Scottish Dental Practice Board. This will assist in lessening the administrative burden on you.

Coloured Clinical Photograph

From 1 October 2011, it is mandatory to submit coloured clinical photographs to obtain approval for orthodontic treatment.


GP17(O) forms, with an acceptance date on or after 1 October 2011, will be declined if they do not have an IOTN Grade at Part 15 when sent in for Prior Approval. The exceptions to this are items;

- 32a1 removable spring and/or screw type appliance
- 32b retention, normally to last for a minimum period of 12 months
- 32c repairs to orthodontic appliances

Compliance and Payment Verification

Monitoring and post-payment verification procedures have been put in place to monitor compliance with the requirement to submit an accurate IOTN Grade. This is to make sure there is no ‘drift’ in grading of the DHC or over scoring of the AC.

We will randomly assess 10% of orthodontic claims with IOTN Grade 5 for each dentist. These assessments will check the accuracy of the IOTN Grade and the appropriateness of the treatment plan. Claims with other IOTN Grades will be monitored in the normal way.

Please be aware that treatment provided, where it is subsequently found to be incorrectly graded, will result in the non-authorisation of payment. We will then recover any interim payments which have been made.

Interpreting Item 32

Guidance on interpreting Item 32 can be found in 2000 PCA(D)17, published in 2000. This guidance is still current.

Useful Links and Documents
IOTN PCA(D)(2011)6
Submission process for each IOTN score
Dental Health Component
Aesthetic Component
GP17(O) Form Filling Guidance
Administration Forms